An RF connector is an electrical connector designed to work at radio frequencies in the multi-megahertz range. Typically, RF connectors are used in a variety of applications such as wireless telecommunications applications, including WiFi, PCS, radio, computer networks, test instruments, and antenna devices. In one application, a plurality of individual connectors are ganged together into a single, larger connector housing for electrically and physically connecting two or more printed circuit boards together.
One example of an RF connector interface is the sub-miniature push-on (SMP) interface. SMP is commonly used in miniaturized high frequency coaxial modules and is offered in both push-on and snap-on mating styles and is often used for PC board-to-board interconnects. For these applications, the conventional SMP interface utilizes a male connector on each of the PC boards and a female-to-female adapter mounted in between to complete the connection. The female adapter is often called a “bullet” and is used to provide a flexible link between the male connectors. This flexible link typically allows 0.020 inches of radial float and 0.010 inches of axial float, where radial float and axial float refer to the ability to tolerate axial and radial misalignment. For example, radial misalignment occurs when the male connector does not line up properly with the female connector (e.g., off-center). When connecting together two PCBs together using a multiple connectors on each PCB (e.g., a grid pattern), radial misalignment can be the result of manufacturing differences in the spacing between the individual connectors on a first PCB relative to the spacing between each of the individual connectors on the second PCB due to manufacturing variance of the PCB or the electronic package where it is mounted. For example, radial misalignment can occur when the tip of a male connector is centered over the center of the receptacle, but the base of the male connector (mounted to the PCB) is off-center. Axial misalignment occurs when a connector mated distance from the corresponding receptacle can vary due to positional tolerance of the PCB and the electronic package. Additionally, often one male connector will be specified as a snap on interface and the other as a push on to ensure that the bullet adapter remains fixed in the same male connector if the PC boards are separated. Bullets are also typically available in multiple lengths to allow for different board spacing.
Another aspect of conventional connectors is that they may support “blind mate” gathering. Generally, a blind mate connector is a connector in which, during the mating process, a human operator can neither see nor feel it to ensure that the connector is correctly aligned. “Blind-mate” refers to a feature that allows an operator to join the connectors without visually seeing the connector interfaces mate. Blind mate connectors typically have self-aligning features which allow for a small misalignment when mating.
Conventional multi-position RF connectors include a conductive inner portion that is surrounded by an insulating outer portion (or “insulator”), where at the mating interface, the insulator is recessed relative to the conductive outer portion. Conventional multi-port RF connectors also typically include a shared conductive outer portion in the form of a common metal body between individual connectors, where the metal body is formed using a manufacturing method such as zinc die casting. Conventional RF connectors with a mechanical float provision typically come in plug-to-plug configurations, meaning that the connector is adapted to male connectors on each end for connecting with corresponding female receptacles.
One problem associated with conventional multi-port RF connectors is that the density of individual connectors is limited by the shape and design of the insulator and conductive outer portion. Specifically, because conventional insulators are recessed relative to the conductive outer portion, the insulator must be at least as large as the conductive outer portion plus additional tolerances. As RF connector applications have begun to require a greater number of individual connections between components, RF connectors using conventional recessed designs have necessarily increased in size to accommodate this. Larger connectors require more physical space in order to provide the necessary contacts, which make the connectors less applicable to high density systems requiring smaller connectors and more expensive to produce.
Another problem associated with conventional RF connectors is that such connectors typically do not have the flexibility to customize the degree of axial or radial float. As described above, float is the tolerance of physical movement of the connectors once mated in a fixed position. Some conventional connectors are configured for high-float applications. For example, when connecting two PCBs, it may be desirable to use a high axial float connector in order to accommodate variations in the distances between various components on the PCBs that are being connected. Alternately, it may be desirable to use a low- or no-float connector when connecting PCBs where a secure fit is achievable and there is less likely to be movement (i.e., stresses) between the PCBs or if the connector contains the aligning features that control position such as close tolerance guide pins. Using conventional connectors, the amount of float provided by connectors is fixed and cannot be applied to either high- or low-float applications without using a different connector.
Accordingly, there is a need for a modular and scalable RF connector for high-density gang mate solutions for both high-float and low-float applications. There is also a need for a high density connector that has a high mechanical float while maintaining high isolation and low-loss electrical performance.